A gun-toting Wisconsin tourist, caught entering the 9/11 Memorial with a loaded firearm over the weekend, said she simply “forgot” she had the piece in her bag, officials said Monday.

Ursula Jerry, 41, of Milwaukee, made her first appearance in court following her arrest Sunday at Ground Zero.

Jerry, charged with criminal possession of a weapon, put her bag on the 9/11 Memorial’s X-ray machine when security officers spotted a .38-caliber Kel-Tec semiautomatic with two rounds in the magazine, officials said.

Jerry told security officers she brought with her on the Amtrak that brought her here from Wisconsin.

“It’s my gun. I forgot I had this,” Jerry said, according to prosecutors.

Jerry has been diagnosed with bi-ploar disorder, said prosecutors, who plan to bring this case to a grand jury.

Defense lawyer Annie Costanzo said she’s been in contact Jerry’s relatives in Chicago, who promised their troubled loved one will make all court appearances in New York if she makes bail.

“Everything she said was truthful,” Costanzo said. “There was no indication of a threat of violence … [and she] certainly had no history of criminal violence.”

A judge set Jerry’s bail at $30,000 and ordered her back to court on Friday.

Jerry wouldn’t be the first dopey tourist to treat the WTC — and the city in general — site like an Old West saloon.

Back in 2011, a Tennessee woman was also busted for bringing a Kel-Tec pistol to the memorial and trying to check it in, like a handbag.

And in July, a Georgia tourist tried to enter the Empire State Building with a loaded gun. He, too, tried to check the weapon at the door, before he was arrested.